Adrian Peterson sat out Thursday's practice because of a sprained left ankle, although the Minnesota Vikings running back is expected to get out of a walking boot and perhaps attempt to practice Friday.

Coach Leslie Frazier said Wednesday that if Peterson can't practice Friday he will be ruled out for Sunday's game at Atlanta. The Vikings did not have media access on Thursday and had a short work day so players could get home to spend Thanksgiving with their families.

Peterson suffered a Grade 1 high ankle sprain and ligament damage in the first quarter of Sunday's loss to Oakland and did not return. That's a more serious injury than a regular sprain, and the Vikings' 2-8 record probably eliminated any thoughts about letting Peterson play without practicing. Peterson was put in a walking boot after Sunday's game.

The Vikings remained shorthanded with tight ends Kyle Rudolph (quadriceps) and Visanthe Shiancoe (hamstring) missing practice for the second day in a row. There is a chance the team will promote undrafted rookie Allen Reisner from the practice squad.